Coolant Flush and Fill

How long has it been since your coolant has been flushed? The sprinter manual calls of for it to be changed every 100k miles. Here is the procedure we did to flush the cooling system on our 2005 T1N 2.7L

You will need of course MB approved coolant. There are a few that are available we choose to go with Zerex G-05 concentrate, and a couple gallons of distilled water.

Your going to want to do this while the engine is cold. DO NOT open the radiator cap when the engine is hot. It will cause the fluid to boil and expand and go everywhere causing serious burns.

First step is to remove the driver side headlight. Remove the headlight you may ask? There is a little screw on the bottom driver side of the radiator that will allow it to drain. So you’ll need to remove the front grill (1 bolt in the middle and 2 push pins) and it slides right up. Then there are 3 Torx screws holding the headlight in place. We were able to move the headlight out of the way just enough to slide a hand back in there to loosen up the drain plug. The hardest part of this whole process was locating the red drain plug. Just keep searching. Its down there.

Placing a container or pan underneath the van, remove the radiator cap, and unscrew the drain plug and catch the fluids so that you can properly dispose of them. When the radiator is drained tighten up the drain plug on the radiator and locate the EGR valve by the intake manifold. Remove the rubber coolant hose thats attached with a hose clamp. Loosen the hose clamp with a flat head screw driver. Now take your water hose and fill up the overflow coolant container which will fill up the radiator and back feed into the cooling system. You should start to see the old coolant coming out of the EGR valve you just took the hose off of. Let that flow till its clear. Now that the water coming out of the EGR valve is clear turn the key to the ON position without turning the van on. You will hear and see the fluid coming from the hose you detached from the EGR. Let that run till both run clear.

We then put the hose back on the EGR valve, made sure the radiator was full and started the engine. let it run to operating temp (just above 180) with the radiator cap off, and repeated the process to make sure we had no remaining old coolant in the system. 2 different types of coolant in the system can have a chemical reaction and cause damage to the internal of the engine. The last time filling it up we used only distilled water.

We then drained it one last time just to be safe. Which you should be draining distilled water at this point. Now its time to add the Zerex. We used 1 gallon of concentrate Zerex (not 50/50) and 2 gallons of distilled water to fill the system. Turn the engine on and you’ll see the system take the fluid out of the coolant overflow. Be sure to keep filling up the overflow container as it gets empty.  Make sure you have no leaks. When it doesn’t take anymore and you are at operating temp, take it for a spin and make sure you are not overheating. we brought a gallon of distilled water with us just incase.

Your cooling system is all freshened up and ready for another 100k miles!